1. Field of the Invention
The present invention relates to a polymeric sheet material having a broad spectrum antimicrobial agent incorporated therein. More particularly, the invention resides in a surgical drape having a broad spectrum antimicrobial agent incorporated in the polymeric material of the drape wherein the antimicrobial agent is released from the drape over a period of time when the drape is applied to the skin.
2. Brief Description of the Prior Art
Human skin is a source of contaminating organisms, since in addition to its normally innocuous bacterial flora, from time to time it may be colonized by pathogenic organisms. Experiments have suggested that pathogenic organisms do not usually survive on normal skin. Under most circumstances, the bacteria of normal skin flora cannot cause wound infection but in the presence of foreign materials, the pathogenic potential of these bacteria appears to be considerably enhanced. Furthermore, the likelihood of bacterial contamination is at a peak immediately preceding, during, and following surgical procedures. Accordingly, to prevent contamination, it is imperative that the skin be effectively disinfected before a surgical incision is made, and during the entire surgical procedure.
Several methods have been proposed to prevent infections associated with surgical incisions. The first method involves applying to the skin surface a topical bactericidally active or antimicrobial agent. These agents typically are in the form of preoperative skin preps, surgical scrub tissues, washes, wound cleaners, lotions and ointments. Although such topical applications are effective for shorter periods of times, their efficacy is limited as a result of their limited delivery time.
U.S. Pat. Nos. 4,542,012 and 4,584,192 propose the application of an antimicrobial agent by depositing a composition having an antimicrobial agent dispersed therein onto human skin and forming an antiseptic film on the skin. In these applications, the film-forming composition is applied to the skin as a liquid solution in a fugitive solvent. Upon contact, the solvent evaporates, leaving on the skin a thin film containing an antimicrobial agent.
Topical application of antimicrobial agents has also been accomplished by using surgical incise drapes which comprise an antimicrobial agent-containing pressure-sensitive layer as an adhesive. For example, U.S. Pat. Nos. 4,310,509 Berglund et al. and 4,323,557 to Russo et al. describe surgical incise drapes which comprise such an adhesive to provide continued asepsis. More specifically, U.S. Pat. No. 4,310,509 discloses a pressure-sensitive adhesive composition which contains chlorhexidene or a complex of polyvinylpyrrolidone and iodine which is applied onto a polymer sheet material, such as polyethylene or polyurethane, for use as a surgical drape. According to the reference, the drape is applied to the skin with the adhesive side contacting the skin so that the antimicrobial agent can be released from the adhesive to the wound prior to and during incision. U.S. Pat. No. 4,323,557 discloses a similar drape, wherein the pressure-sensitive adhesive comprises n-vinylpyrrolidone residues in the polymer backbone. Iodine is complexed with these residues.
U.S. Pat. Nos. 4,340,043 and 4,460,369 to Seymour disclose polymeric sheet materials having an adhesive layer, wherein an antimicrobial is disseminated throughout the adhesive layer. The antimicrobial is preferably a silver sulphadiazine. In use, the polymeric material is applied to the skin, adhesive side down.
Similarly, U.S. Pat. No. 4,643,181 to Brown discloses a surgical dressing or incise drape material containing a substrate coated with an antimicrobial containing adhesive. The antimicrobial is polyhexamethylene biguanide hydrochloride, and the dressing or drape is applied to the skin such that the adhesive directly contacts the skin.
U.S. Pat. No. 4,675,347 discloses an antimicrobial latex composition suitable for use in the manufacture of medical devices and the like, and in particular, urethral catheters. The composition is made from a cationic latex composition having incorporated therein a cationic antimicrobial agent. The references does not disclose the use of the latex as a surgical drape.